Steps are:
Open the challenge in Online Review.
Click on the “Edit Project” button.
Add yourself as a checkpoint reviewer using OR.
Click on “submit scorecard”.
Select rating 10 for the first place winner, rating 9 for the second place winner and so on.
If you wish to fail the submission, select rating 1 and add comments then click on “save and mark complete” button.
Please note, you have to submit scorecards for all the submissions to close the checkpoint review phase and announce the winners.